Loss of CSAR1 causes retention of maternal cytoskeleton in the residual body. (A and B) Maximum intensity Z-projections of confocal stacks of (A) ERK7^AID and (B) Δcsar1 parasites grown in the absence of IAA. Parasites were visualized with GFP-tubulin (green), and antibodies against the inner membrane complex marker IMC1 (red) and ERK7 (blue). Apical ends of parasites are indicated with white arrows. Retained cytoskeleton from the previous two divisions in the Δcsar1 vacuole is indicated with orange arrows. Scale bars are 5 μm.